Benchmarks: AMD64 vs i386 on Dual 246 Opteron

[ray at redshift.com]

At 08:38 AM 7/29/2005 -0400, Martin Cracauer wrote:
| ray at redshift.com wrote on Fri, Jul 29, 2005 at 02:32:34AM -0700: 
| > At 07:35 PM 7/28/2005 -0400, Martin Cracauer wrote:
| > | > While this sounded like a long shot, I loaded FreeBSD 5.4 i386 on the
machine
| > | > and after applying the exact same configuration to the OS, Apache, PHP and
| > | > MySQL, re-ran the benchmarks.  Much to my surprise, just changing the OS
| > from 64
| > | > bit to 32 bit caused the machine to double in speed.  The results are
attached
| > | > in an Excel spreadsheet.  So the exact same machine, running the identical
| > | > configuration, performed roughly twice as fast when running FreeBSD 5.4
i386 vs
| > | > FreeBSD 5.4 AMD64.  Something about this seems so wrong to me :-)
| > | 
| > | I'm sorry but I cannot support these findings.  I don't have
| > | cut'n'paste numbers handy, but generally 64 bits speed up things quite
| > | a bit for me.  I have seen slowdown in 64 bit mode in e.g. bzip2 but
| > | generally there is a speedup.
| > 
| > On the AMD64, I am pretty sure that I did *not* include the following lines
like
| > I normally do on the i386:
| > 
| > options         SMP                     # Symmetric MultiProcessor Kernel
| > device          apic                    # I/O APIC
| 
| I occurse to me that not using one of the two CPUs might have
| something to do with a performance drop of approximately 50% :-)
| 
| Martin

:-)  Stay tuned for "son of benchmarks" when I get our next Dual Opteron 246 in
here!

This may be operator, not "opteron" error after all - hehe :)

Ray